Magnetic work-holder.



No. 843,312. PATENTED EEB. 5, 1907. W. N. VANGE. MAGNEHG WORK HOLDER.

APPLICATION FILED SEPT.20,19OG.

mlrmmmmm/ 1111 W l supplement orlift-piece so constructed as to other,for urposes of adjustment as to height but whether the magnetic ho deris made nois, have invented a new and u seful 1m l 22 are the trate theuse of a set of them of varying par nur oFFIoE.

y UNITED sra-'ras l i WALTER N. vANic," or CHICAGO, iLLiNoIs.

` lwlAc-im'irlc: wom-HOLDER.

Specification of Letters Patent.

I l Application filed September 20, 1906. Serial No. 335,398.

To all whom it .may concern,.- -V l such holders a set of thesupplementary lifts Beit known that I, WALTER N. VANoE,-a herein to bedescribed. l' citizen of the United States, residing in Chil In the saiddrawings, 20 represents the bed cago, in the county of Cook and State ofllliof an ordinary shaping-machine.

' holding-magnets that hold the Work 21 to the bed by magneticattraction.

23 is one of the supplementary lifts shown in position at Figs. 2 and 4,and 24 is the cutting-tool to operate on the work held on the bed ortable.

The holding-magnet selected to illustrate is the simplest form of aone-part magnet composed of the outer steel shell 221, the coil 222,connected to an electric current, the inner steel core 223, and thecopper closingplates 224.

The supplementary lift 23, as illustrated, is made in circular form tocorrespond to the form and size of the holder-magnet and is shown tobecomposed of an outer ring or shell 231, corresponding in size andshape laterally with the shell 221 of the magnet, an

provement in Magnetic Work-Holders, of i which the following isaspecification. Y l

This invention relates to an improvement in magnetic work-holders; andit consists in providing the ordinary work-holder with a lift theWork-holder magnet a determined distance above the bed of the machine,and thus lift the work that much farther up, and at the same time tocause the magnet to be attracted by the bed by reason of the'lines offorce about said holder-magnet being compelled to pass through the metalof the bed morder to complete their` circuit. Thisl is accomplished bymaking the supplement or lift in two parts or pieces of magnetic metal,as steel, and separating the two pieces by a piece of non-magneticmaterial, as copper, the whole being so arranged that the magneticmaterial will prolong the poles of the workholder-magnet.

In the accompanying drawings, which form a part of this specification,Figure 1 represents a top or plan view of one of my improvedsupplementary lifts. Fig. 2 represents a vertical section of a portionof a machine-bed to which work is to be held, of the -work to be soheld, of an ordinary workholding magnet, and of one of my supplementarylifts. Fig. 3 shows an edge view of a series of the supplementary liftsto illussponding in lateral dimensions with the coil of the magnet, andan inner core 233, corresponding to the core of the magnet. The outershell 231 and the inner core 233 of the lift are made of magnetic metal,steel preferred. p

In Fig. 3 a series or set of the lifts such as is above described isshown, the set consisting of six different thicknesses of lift, thethickest being one inch in height, the next half an inch, the nextone-fourth of an inch, the next three-sixteenths of an inch, the nextone-eighth of an inch, and the next onesixteenth oi an inch. By use ofsuch a series employing a single lift or more than one piled togetherany ordinary .amount of required raise of the hold ing-magnet may beattained.

The lift or lifts are used as follows: Suppose a piece of work is to beheld to the bed and its upper surface milled to a plane parallel to itsunder surface or some part thereof, a condition that often happens, andsuppose, further, that the under surface of the piece has a shoulder oroffset-for example, like the piece of work shown in the machine at Fig.Li-also a thing that often occurs, and it is desired to hold the piecewith the upper surface true and solid, and yet in such manner that thepiece may be easily and quickly replacedwhen finished by another of thesame kind. To do this, the workman selects a lift of the same thicknessor heightasthe thicknesses in aliquot parts of an inch, and Fig. 4`is afragmentar elevation of a machine-bed with the wor thereon and held by amagnetic Work-holder by aid of one of my su plementary lifts.

my patent No. 807,517, dated Decemof two magnets, one movable upon theor as to re ative inclination of the up er and lower poles orholding-faces. These olders may be used handily to hold almost any kindof work, even though made onl in one part;

thus in one part in the form of a rigid integer or in two parts, onemovable on the other and involving two energizing-coils, l find itextremely convenient to provide for use with Patented Feb. 5, 19m.

intermediate copper annulus 232, corre-4 ICC offset 4or shoulder andplaces it under one of the magnets. This makes the two magnets ofdiffering heights, one being higher than the other by the depth of theshoulder 5 or offset, so that the upper surface of the. piece of work ismaintained parallel to the ace of the bed, and consequently parallel tothe under face of the ieee. The reason why the supplementary lift isable to hold the io work to the bed is becausethc construction of thelift is such that the lines of magnetic force cannot return-tothemselves without passing through the bed ofthe machine when the liftis used. These lines are represente-1l I 5 by the dotted lines in theFig. 2, for example. It will be seen that to complete the circuit ofthese lines throughl magnetic metal they must pass through the workabove and also through the bed below, as they will not go l ze throughthe copper annulus.

By combining with the set of magnetic holders-three usually constitutingsuch set-a set of the supplemental lifts to eoact therewith and with theWork of magnetic 25 metal and the machine-bed of magnetic` metal almostany piece of work7 however troublesome its offsets, can be held andsuecessfully milled, the lifts ofvarying thickness enabling the workmanto adjust the piece so 3o that its upper surface will be in the properplane'to be cut as desired, and this can be done with magnets-,of anintegral core.`

I elaim- 1. The supplemental lift for work-holder magnets consisting ofa core and shell, corre- 35 sponuing to the core and shell of the magnetand made of magnetic metal, and a (livi..ing

art made of non-magnetic material, wheref y, when the lift is used witha holding-magnet the lines of force are compelled to go 4o through themachine-bed and thus to polarize the lift; substantially as specified..

2. The combination with the machine-bed of magnetic metal, and themagnetic workholder, designed to hold a piece of work of 45magnetic-metal work to said bed, of a supplementary lift, made ofmagnetic metal in shapeand form to correspond to the magnetic metal ofthe holding-magnet, and having non-magnetic parts so arranged that, 5owhen the lift is placed between the magnet and the bed, or attractedpart, the lines of magnetic force will be compelled to pass through thesaid bed or attracted part; substantially as specified..

WALTER N. VANCE.

Witnesses:

H. M. MUNDAY, PEARL ABRAMS.

